Green synthesis of β-CoMoO4 nanowires catalyst for organic dye photodegradation

This paper presents a simple and low-cost one-step synthesis method of cobalt molybdates. Several structural, optical, and catalytic characterization techniques are used in synergy to highlight the properties of the synthesized material. EDX, FTIR, and X-ray diffraction analysis confirmed the formation of the pure β-CoMoO4 phase. The obtained β-CoMoO4 particles are polydisperse with quasi-agglomerated nanowires shape and the diameters are estimated in the range (115 ± 22) nm by atomic force microscopy (AFM). In addition, the band gap energy, Eg = 2.81 eV, shows that β-CoMoO4 nanowires can absorb in the near-UV visible range and act as a photocatalyst. A photocatalytic activity against methylene blue (MB) degradation of up to 52 % was observed under visible light irradiation. As a result, a pseudo-first-order kinetic rate constant of MB photodegradation, in the presence of β-CoMoO4 nanowires, was estimated to be 0.013 min−1. The photodegradation efficiency of the synthesized material could be mainly related to the positions of the conduction (ECB = 0.23 eV) and valence (EVB = 3.04 eV) potential energies, which are favorable to the generation of reactive oxygen species (ROS). Moreover, the sample was recovered from the solution by simple centrifugation and reused three times without significant loss in photocatalytic activity. We experimentally prove that the synthesized nanowires show strong photodegradation efficiency and photocatalytic stability for three consecutive cycles.